1. Technical Field
The present invention relates to a touch sensor.
2. Description of the Related Art
In accordance with the growth of computers using a digital technology, devices assisting computers have also been developed, and personal computers, portable transmitters and other personal information processors execute processing of text and graphics using a variety of input devices such as a keyboard and a mouse.
While the rapid advancement of an information-oriented society has widened the use of computers more and more, it is difficult to efficiently operate products using only a keyboard and a mouse currently serving as an input device. Therefore, the necessity for a device that is simple, has minimum malfunction, and is capable of easily inputting information has increased.
In addition, current techniques for input devices have progressed toward techniques related to high reliability, durability, innovation, designing and processing beyond the level of satisfying general functions. To this end, a touch sensor (touch panel) has been developed as an input device capable of inputting information such as text, graphics, or the like.
This touch sensor is mounted on a display surface of an image display device such as an electronic organizer, a flat panel display device including a liquid crystal display (LCD) device, a plasma display panel (PDP), an electroluminescence (El) element, or the like, and a cathode ray tube (CRT) to thereby be used to allow a user to select desired information while viewing the image display device.
Meanwhile, the touch sensor is classified into a resistive type, a capacitive type, an electromagnetic type, a surface acoustic wave (SAW) type, and an infrared type. These various types of touch sensors are adapted for electronic products in consideration of a signal amplification problem, a resolution difference, a level of difficulty of designing and processing technologies, optical characteristics, electrical characteristics, mechanical characteristics, resistance to an environment, input characteristics, durability, and economic efficiency. Currently, the resistive type touch sensor and the capacitive type touch sensor have been used in a wide range of fields.
At present, as the capacitive type touch sensor, the touch sensor using an indium-tin oxide (ITO) or conductive polymer metal and a metal mesh electrode has been used. However, the touch sensor using the metal mesh electrode makes patterns look visible, and therefore visibility may be degraded.